From the viewpoint of energy saving, a vehicle requires high fuel economy, and public attention is drawn to an electric vehicle that is driven by a motor or a hybrid vehicle that is driven by a combination of a motor and an engine. It is difficult to drive or control a high capacity vehicle-mounted motor for a vehicle using a direct current voltage of a battery, and an electric power conversion apparatus that uses the switching of a power semiconductor element is essential to boosting and alternating current control of the high capacity vehicle-mounted motor. In addition, since the power semiconductor element generates heat due to electrification, a power module on which the power semiconductor element is mounted requires an insulation layer that has a high heat dissipation capacity.
For example, in the power module, a structure is known where laminated bodies of which each is configured to have a power semiconductor chip, a conductor plate on which the power semiconductor chip is mounted, a metal base plate on which the conductor plate is mounted, and a ceramic plate that insulates the conductor plate and the metal base plate from each other are packaged in a resin case to form a structure body, and the structure body is attached to a cooling body. In the invention disclosed in PTL 1, as an example of cost reduction, a ceramic thermal spray film is formed on a side of a heat dissipating surface of the conductor plate sealed in a resin, and the film serves as an insulation layer.